Our Staff

Dr. Silva specializes in minimally invasive bariatric surgery. He is known as one of the early adopters of the gastric sleeve technique and is among the most experienced surgeons in the New York area in Laparoscopic Sleeve Gastrectomies. He received advanced training in laparoscopic surgery at Baptist Hospital in Miami, FL and received his medical training at Albert Einstein College of Medicine / Montefiore Medical Center, Mount Sinai School of Medicine and University of Medicine and Dentistry of New Jersey / Robert Wood Johnson.

Spencer E. Amory, MD, FACS
Clinical Professor of Surgery, Columbia University College of Physicians and Surgeons

Dr. Amory, Chief of the Division of General Surgery at NewYork-Presbyterian Hospital/Columbia University Medical Center, received his medical training from Johns Hopkins and Columbia Universities. He developed techniques in laparoscopic cholecystectomy that enabled his group to have the lowest open cholecystectomy rates in the state. In addition, Dr. Amory has earned a reputation for his diagnostic acumen in complex surgical problems and fir highly individualized and personalized care. In 2007, he received Columbia's Leonard Tow award for humanism in medicine.

Marc Bessler, MD, FACS
Clinical Professor of Surgery, Columbia University College of Physicians and Surgeons

Dr. Marc Bessler is Clinical Professor of Surgery at Columbia University College of Physicians and Surgeons. A fellow of the American College of Surgeons, Dr. Bessler’s clinical specialties include laparoscopic and single incision bariatric surgery. He earned his medical degree from New York University School of Medicine, and completed his residency in general surgery and his fellowship in surgical endoscopy at NewYork-Presbyterian Hospital in New York City.

Leaque Ahmed, MD, FACS
Assistant Clinical Professor of Surgery, Columbia University College of Physicians and Surgeons

Dr. Ahmed was trained in endocrine and pancreatic surgery at Columbia University Medical Center and serves as Director of Bariatric Surgery at Harlem Hospital Center, where he has performed hundreds of minimally invasive weight loss procedures. In addition to bariatric surgery, he specializes in minimally invasive thyroid and parathyroid surgery and pancreatic surgery.

Preya Ananthakrishnan, MD
Assistant Clinical Professor of Surgery, Columbia University College of Physicians and Surgeons

Dr. Ananthakrishnan is a board certified breast surgeon and Assistant Professor of Clinical Surgery at Columbia University College of Physicians and Surgeons, New York, NY. She received her medical degree from the University of Louisville School of Medicine in Louisville, Kentucky and completed her residency in General Surgery at the New Jersey Medical School in Newark. Additionally, Dr. Ananthakrishnan completed a fellowship in Breast Oncology at the John Wayne Cancer Institute in Santa Monica, California.

Allen B. Chefitz, MD
Assistant Clinical Professor of Surgery Columbia University College of Physicians and Surgeons

Dr. Chefitz is a Board-certified surgeon, specializing in laparoscopic surgery and the use of biomaterials, with interests in hernia and breast research. He received his surgical training from Montefiore Medical Center / Albert Einstein College of Medicine and his medical training from the University of Massachusetts Medical School in Worchester. He also has extensive experience in surgical quality assurance.

Aaron Roth, MD, FACS
Assistant Clinical Professor of Surgery

Dr. Roth specializes in general and bariatric surgery with an emphasis on minimally invasive techniques. He is a former member of the Institute for Minimally Invasive Surgery in White Plains, NY, that was a center for education and training for minimally invasive surgeons. He received his medical degree from the Chicago Medical School and surgical training at Lenox Hill Hospital in NY, with a fellowship from the University of Pittsburgh Medical Center.